That is not official, unmaintained since November 2024, and only applicable for the business API. It wouldn't allow someone to create a WhatsApp client for a non-Android/iOS platform.
This is why iMessage is much better than SMS - there is an implicit cost to send. This is why there is 100x (my experience) iMessage spam than SMS spam. Easy to send messages -> spam
> better than SMS - there is an implicit cost to send
Funnily enough, people being charged per SMS but being allowed to send as much messages as they need on apps like WhatsApp is exactly why SMS/MMS is barely used on a large scale outside of North America.
I rarely receive any spam on my phone. WhatsApp/Telegram/Signal do have the occasional obvious bot, but all apps make it trivial to block and get rid of any of them.
All phone and internet services in the EU are connected to your personal identity document, similar to China. If you send spam, the police come to your house.
It’s already possible to make WhatsApp bots, if the API was official they could moderate it better if anything so I don’t see how it would help with spam